search for: my_convention

Personally, I'd love to see a setup where instead of LLVM implementing each calling convention and ABI hack, we provide a means of actually describing this. Specifically, I'd love to see a design for how to specify in the IR which register(s) (if any register(s)) a particular value should be placed into. Don't get me wrong, I don't have any good ideas about how to do this, I'm

Functions with __attribute__((fastcall)) pop their arguments and take up to two arguments in ecx and edx. Currently we represent them by just setting the x86_fastcallcc calling convention. The problem is that the ABI has some strange conventions on when a register is used or not. For example: void __attribute__((fastcall)) foo1(int y); will take 'y' in ecx, but struct S1 { int x; };